1. Field of the Invention
The present invention relates to a novel material handling system, and more particularly to an improved process for sorting mail.
2. The Prior Art
As is known, mechanized mail processing systems typically use operating keying stations where the mailpiece is physically presented directly to the operator for reading and keying of the address information. These systems are noisy and are often located on the dusty workroom floor. To provide improved operator environments, remotely located video display (RVD) systems have been developed. These systems use mechanical transports with cameras or scanners which are located on the workroom floor to process the actual mailpieces, while the operators are normally located in enclosed adjacent areas. The enclosed areas can be environmentally controlled to improve the operators' working conditions. To provide the time necessary for keying the mailpieces, mechanical delay loops or buffers hold the mailpieces in transit while the video information is being sequentially processed by the operators. Since the delay loops or buffers are mechanical, they are designed for fixed periods of time. The length of the loop is normally dependent upon the maximum number of coding consoles that are configured with the specific system. This loop is used for pipeline processing, which means that the operator must key the address information within the delay period or the mailpiece is rejected. Recirculating loops to permit a mailpiece to go through the delay loop a second time have also been proposed. In any event, if the delay loop fills with mailpieces, the feeder is inhibited in order to stop the introduction of new mailpieces until those within the loop are processed. Thus, the throughput of the system is directly dependent upon the number of operators on the system and the keying rate of each, with an additional loss due to items that cannot be coded within the time queue.
Attempts have also been made to integrate on-line the concept of remote video with optical character recognition. These attempts have generally met with failure. The major problems are the mechanical delay loop, which determines how many items can be queued for processing, and the nonhomogeneous nature of the input mailstream. If, for example, the loop fills with items which cannot be read by an optical character reader (OCR), the feeding mechanism is normally stopped. Thus, if there are not enough operators on duty and a run of OCR unreadable mail is encountered, the system stops feeding when the delay loop fills up. The feeder remains off until the queue goes down to some preset level. If a quantity of OCR readable mail is at the feeder ready for processing, the feeder remains off until the preset level is reached. Thus, overall throughput is reduced. On the other hand, if the system is staffed with a full complement of operators and a run of OCR readable mail is encountered, the operators could remain idle. A possible solution to this problem would be to switch images from a stand-alone video system to the OCR/video system. However, this would affect the loading or throughput of the stand-alone system. Another approach which has been proposed is to multiplex the operator terminals across many machines. This minimizes the problems in larger post offices where many OCRs would be installed, but fails to work as a solution when mail volume is low, such as early in the day when only one or two OCRs are operating. It also fails to work in smaller post offices whose volume can only justify one or two OCRs.